I live in East Kilbride and have been studying the local history for some time. Calderwood Castle in my research has no mention of being ever owned by a member of a Calderwood family. It was owned from the end of the 14th century by the Baronets Maxwell of Calderwood, extending it in the 19th century until it was sold to the Scottish Co-Operative Society in 1904 and demolished in 1955. The title Baronet of Calderwood passed onto the Barons of Farnham.
Very little of the building is left, a wall some stairs and a pile of half buried rubble being the ruins.
I do have pictures of what it looked like, and what it looks like now so if you would like to see you can contact me on firstname.lastname@example.org